R.F. Thelen

A 2 MW flywheel for hybrid locomotive power

The University of Texas at Austin Center for Electromechanics (UT-CEM) is currently developing an Advanced Locomotive Propulsion System (ALPS) as part of the Next Generation High-Speed Rail program sponsored by the Federal Railroad Administration (FRA). The ALPS consists of a gas turbine and synchronous alternator, combined with an induction motor coupled flywheel energy storage system (FESS). The prime power and FESS are coupled through a DC power link, as is the conventional AC traction drive system. The energy system includes auxiliary support systems to provide thermal management, bearing systems, controls, and power conversions. The energy exchange capacity of the flywheel is 360 MJ (100 kW-hr). This paper presents the requirements, considerations, and design of the integrated turbine and flywheel power system. Significant development efforts have gone into the high-speed synchronous alternator, the flywheel power converter, and the highspeed induction machine for the flywheel, the flywheel itself and its magnetic bearings. The fabrication status of these components and testing progress is also reported.

A field based, self-excited compulsator power supply for a 9 MJ railgun demonstrator

Fabrication efforts have begun on a field-based compulsator for firing 9 MJ projectiles from a railgun launcher. The machine is designed to store 200 MJ kinetic energy and fire a salvo of nine rounds in three minutes at velocities between 2.5 and 4.0 km/s. Prime power required to meet this firing schedule is 1.865 kW, and will be supplied by a gas turbine engine. It is also possible to fire a burst of two shots in rapid succession, if desired. Operating speed of the machine is 8250 r/min and it has design ratings of 3.2 MA peak current and 20 GW peak power into a 9 MJ railgun load. A two-pole configuration is used for pulse-length considerations, and selectivity passive compensation is used to produced a relatively flat pulse and limit peak projectile acceleration to about 980000 m/s/sup 2/. Other distinguishing features include an air core magnetic circuit, separate rotor armature windings for self-excitation and railgun firing, ambient temperature field coils, and excitation field magnetic energy recovery capability. A detailed description of the machine as designed, and its auxiliary and control systems, is provided. Fabrication and assembly methods are reviewed, and the current status of the project is discussed. >

Testing of a rapid-fire compensated pulsed alternator system

A compensated pulsed alternator (compulsator) has been designed and fabricated to drive a rapid-fire railgun system. Initial testing of the compulsator resulted in the failure of the compensation shield at full speed. An ambitious rebuild effort was undertaken, allowing testing to begin in August 1987. Since then, several rapid-fire shots have been performed, firing two 3 m guns at a 60-Hz repetition rate. A 65-g solid armature projectile was accelerated to 1.8 km/s during the initial tests with the compulsator operating at half-speed and reduced excitation. These preliminary results suggest a high probability that the compulsator rapid-fire system will meet and exceed the design goals. >

A rapid fire, compulsator-driven railgun system

It is becoming clear that compensated pulsed alternators (compulsators) are the preferred power supply for rapid-fire railgun systems. High efficiencies, inherently high repetition rates, and the elimination of high current opening switches are the primary advantages of compulsator-driven systems. The benefits and capabilities of these systems will be demonstrated in a project which is currently in the final stages of fabrication. The goals of this project are to accelerate a burst of ten, 80-g projectiles to 2 km/s at a 60 Hz rate of fire. Details of the compulsator design, the design, fabrication, and testing of system components, and proposed operation are presented.

The CEM-UT rapid-fire compulsator railgun system-recent performance and development milestones

Twenty-seven compulsator-powered railgun experiments have been performed, including a 1.0 MJ discharge at 3510 r/min. In this test, a 724 kA current pulse accelerated an 80 g, aluminum armature to 2.05 km/s, thus exceeding the projectile velocity goal at 73%-rated machine speed. Furthermore, operation with a single gun barrel has been achieved using a parallel path, solid-state closing switch to deliver 132 kA to the railgun injector. The latest data are presented from the rapid-fire compulsator railgun facility. Included is a discussion of the energy transfer, power output, and system efficiency during a 1.0 MJ discharge. Also shown are the injector current, voltage, and di/dt curves for this test which were used in the design of the solid-state closing switch. Results of railgun experiments using the solid-state switch are analyzed. >

Status of the 9 MJ Range Gun system

The 9 MJ Range Gun system under construction at the Center for Electromechanics at The University of Texas at Austin is designed as a self-contained, field portable electromagnetic launch system to accelerate a salvo of three projectiles to a muzzle energy of 9 MJ at velocities ranging from 2.5 to 4.0 km/s. The Range Gun system will consist of a self-excited air-core compulsator, a 90 mm bore railgun launcher, prime power and auxiliary systems, solid state switches for field rectification and gun discharge, and the controls and data acquisition required to operate the system. The compulsator is designed to deliver 3.2 MA current pulses to the railgun launcher at a peak power rating of 10 GW. This paper describes some of the innovations incorporated into the design of the 9 MJ Range Gun system compulsator and presents the status of the fabrication and testing efforts. Initial performance of the 90 mm railgun during testing at the Electric Armaments Research Center will also be presented. >

Advanced Locomotive Propulsion System (ALPS) Project Status 2003

The University of Texas at Austin Center for Electromechanics (UT-CEM) is currently engaged in the development of an Advanced Locomotive Propulsion System (ALPS) for high speed passenger rail locomotives. The project is sponsored by the Federal Railroad Administration as part of the Next Generation High Speed Rail program. The goal of the ALPS project is to demonstrate the feasibility of an advanced locomotive propulsion system with the following features: • Operation up to 150 mph on existing infrastructure • Acceleration comparable to electric locomotives • Elimination of

Status of the Advanced Locomotive Propulsion System (ALPS) Project

3-5M per mile electrification costs • Fuel efficient operation with low noise and exhaust emissions The propulsion system consists of two major elements: a gas turbine prime mover driving a high speed generator and an energy storage flywheel with its associated motor/generator and power conversion equipment. The 2.5 MW high speed generator is a three phase, eight pole synchronous machine designed to directly couple to a 15,000 rpm gas turbine. Power from the turbine/alternator system feeds the locomotive dc bus through a conventional full bridge rectifier. The energy storage flywheel features a graphite/epoxy composite rotor operating on active magnetic bearings and is designed to store 480 MJ at 15,000 rpm. An induction motor/generator and variable frequency motor drive provide the link to the dc bus and are used to control power flow into and out of the flywheel. In addition to design and fabrication of the propulsion system components, the project is also developing a distributed control system with power management algorithms to optimize the hybrid propulsion system. Fabrication of the major components of the propulsion system is nearing completion and some preliminary testing of the flywheel and high speed generator has been completed. After completion of the laboratory testing, the propulsion system will be integrated onto a locomotive platform for rolling demonstrations at the Transportation Technology Center test track in Pueblo, Colorado. The paper presents an overview of the propulsion system operation and control strategies, gives detailed descriptions of the major components, and presents component test results.

Development of a 3 MW High Speed Generator and Turbine Drive for a Hybrid Vehicle Propulsion System

The University of Texas at Austin Center for Electromechanics (UT-CEM) is currently engaged in the development of an Advanced Locomotive Propulsion System (ALPS) for high speed passenger rail locomotives. The project is sponsored by the Federal Railroad Administration as part of the Next Generation High Speed Rail program. The goal of the ALPS project is to demonstrate the feasibility of an advanced locomotive propulsion system with the following features: • Operation up to 150 mph on existing infrastructure • Acceleration comparable to electric locomotives • Elimination of

Testing of a 3 MW High Speed Generator and Turbine Drive for a Hybrid Vehicle Propulsion System

3-5M per mile electrification costs • Fuel efficient operation with low noise and exhaust emissions The propulsion system consists of two major elements: a gas turbine prime mover driving a high speed generator and an energy storage flywheel with its associated motor/generator and power conversion equipment. The 2.5 MW high speed generator is a three phase, eight pole synchronous machine designed to directly couple to a 15,000 rpm gas turbine. Power from the turbine/alternator system feeds the locomotive dc bus through a conventional full bridge rectifier. The energy storage flywheel features a graphite/epoxy composite rotor operating on active magnetic bearings and is designed to store 480 MJ at 15,000 rpm. An induction motor/generator and variable frequency motor drive provide the link to the dc bus and are used to control power flow into and out of the flywheel. In addition to design and fabrication of the propulsion system components, the project is also developing a distributed control system with power management algorithms to optimize the hybrid propulsion system. Fabrication of the major components of the propulsion system is nearing completion and some preliminary testing of the flywheel and high speed generator has been completed. After completion of the laboratory testing, the propulsion system will be integrated onto a locomotive platform for rolling demonstrations at the Transportation Technology Center test track in Pueblo, Colorado. The paper presents an overview of the propulsion system operation and control strategies, gives detailed descriptions of the major components, and presents component test results.